Slotting knife



' Dec. 23, 1941. BARNEY 2,267,517

SLOTTING KNIFE Filed March 6, 1941 2 Sheets-Sheet l ZOE Ymeman 'bame} I127 -;-l6 Big Q a4. Atbmeg g 7 Dec. 23,1941.

I F. BARNEY 2,267,517

SLOTTING KNIFE Filed March 6 1941 Sheets-Sheet 2 Patented Dec. 23, 1941UNITED STATES PATENT OFFICE SLOTTING KNIFE Freeman Barney, Spring Lake,Mich., assignor to The Challenge Machinery Company, Grand Haven, Mich.,a corporation of Michigan Application March 6, 1941, Serial No. 382,03612 Claims. (c1. 164-50) This invention relates in general to drillingand slotting machines which drill holes in and provide slots at theedges of sheets of paper which are to be used in loose leaf binders. Myinvention in particular is directed to a novel form of slotting knifeadapted to be used on machines of this character. The operation anddetails of machines of this type are well-known to those skilled in theart and for a moreclear understanding of such operation and themechanical parts of the machine reference may be had to the co-pendingapplication bearing Serial No. 218,552, filed July 11, 1938.

In the operation of the machine a pack of paper sheets is located on atable, and the carriage having the slottingknife secured thereto isreciprocated and is moved to and through the pack tocut the slot in theedge thereof. When this occurs a stack of paper chips results from thecutting operation, and has long been a source of concern to operators ofsuch machines to successfully remove these paper chips from the vicinityof the slotting knife so that they will not interfere with thesucceeding operation thereof.

It is a further object of this invention to formv openings in the sidesof the slotting knifewhich.

cooperate with suction means adjacent thereto in removing the paperchips. l

A still further object of the invention is the provision within thesides of the. slotting knife of camming means to force the paper chipsaway from the edge of the pack of paper sheets. as they are being cut totherebyrender. the cooperation of the suction means andthe slots in theknife more eflicient. A Other objects and purposes of the invention willappear more fully as the description proceeds. l l I 1 To theaccomplishment of the foregoing and. related ends said invention, then,consists ofthe,

means hereinafter fully described and .parti'cu- Fig. l is. afragmentary partvertical section 55 and part side elevation of a machineembodying one form of my invention. v

Fig. 2 is a fragmentary plan view of the slotting I knife with portionsof the machine thereabove removed.

Fig. 3 is an enlarged vertical section through which it is secured.

Fig. 4 is a horizontal section through the device of Fig. 3.

Fig. 5 is a fragmentary plan view of a sheet of paper showing the formof slot cut in the edge thereof and made by the form of cutting knifeshown in Fig. 4.

Fig- 6 is a vertical section through a modified form of slottingknifetogether with the carriage on which it is mounted.

Fig. 7 is a horizontal section through the slotting knife of Fig. 6. r a

Fig. 8 is a fragmentary part sectional and part elevational view of aportion of the machine showing a still further modified form of slottinknife 'mounted thereon together with the continuously rotating hollowdrill.

Fig. 9 is an enlarged vertical section through the slotting knife ofFig. 8. but showing the tubular drill in side elevation.

Fig. 10 is a horizontal section through the device shown in Fig. 9 takensubstantially half way between the upper and lower ends of the slottingknife.

Fig. 11 is also a horizontal section through the device of Fig. 9 buttaken adjacent the bottom fore as may be more clearly seen by reference.

to the copending application abovementioned. These means, however, havenot operated satisfactorily to those concerned and I have found.

that one means of increasing the ,efilciency of this removal is to placeslots in the sides of the slotting knife. The chips which are removedfrom the edge of the pack of paper sheets will be received between thesides of the slotting knife, whether these sides be parallel ordiverging, and the suctionwhich is createdadjacent the knife at. theendof its cutting stroke will operate more successfully to remove thesechips when thesides of the knife are slotted. This efliciencyis fur.-

section through the ther increased by the use of camming means withinthe sides of the knife which force the paper chips away from the edge ofthe pack as they are being cut, all as more fully described hereinafter.

When the paper chips are first cut and are received between the sides ofthe cutting knife their edges will curve downwardly and there will be aconsiderable amount of side pressure against the chips as well as thechips having a certain amount of pressure outwardly against the sides ofthe knife by reason of their tendency to straighten out and lie flat.This pressure must be relieved in order to permit the machine tofunction properly inasmuch as such pressure may spread the sides of theknife. Also, it is difficult to remove the chips by the use of a suctionwhen this side pressure is present. By the combined use of the cammingmeans and the opening in the sides of the knife, after the clips reach acertain height upwardly from the cutting edge of the knife, the openingswill permit the chips to expand and lie flat in a loose condition whichenables the suction to efficiently withdraw them from the vicinity ofthe cutting knife.

Referring now more particularly to the drawings, the machine includes asupporting base I having a table 2 located thereon for the purpose ofsupporting a pack of paper sheets 3. An insert of wood or other suitablematerial 4 is located within the table 2 and directly beneath thereciprocating knife so that its cutting edge will not be dulled bycoming in contact with the metallic surface of the table.

A back gauge 5 is adjustably mounted on top of the table 2 and is soformed that intermediate its ends and at spaced apart points it has therearwardly extending portions 6 connected together by the bar I, so thatbetween the confines of the two parts 6 and the bar 1 a recess is formedwithin which the slotting knife is received in its lowermost position,

An opening is provided in the table 2 to receive a tube 8 with which isassociated the necessary mechanism for creating a suction therein. Withreference to Fig. 2 it is to be seen that the upper end of thetube 8terminates in the upper plane of the table 2 within the recess formed inthe back gauge 5 and immediately behind the insert 4. This is one formwhich the suction tube may take. It will be obvious that the particularlocation of the end of the suction tube will not be material so long asit terminates adjacent. the cutting knife. In other words. it may alsobe possible to have the tube 8 above the table and terminate within therecess formed in the back gauge, the specific location being a merematter of choice.

Above the table is located the head of the machine 9 which has locatedthereon the vertically reciprocating carriage In having the slottingknife ll secured thereto. Immediately in front of this knife is apresser foot I2 which has the rod l3 located thereabove which issurrounded by a compression spring 14. This operates to hold the pack ofpaper sheets in position during the cutting operation and the springwill compress after the top of the pack is reached and the knifecontinues downwardly.

The particular form of slotting knife shown in Figs. 1 to 5 comprisesrearwardly extending portions I5 having openings therein through whichthe screws I'S pass to rigidly secure the knife to the carriage Ill. Thetwo sides then extend toward each other for a short distance-as at IT,

then extend forwardly in parallelism as at I 8 and the two cuttingblades are connected together at their forward ends by the curvedportion I9. Either one or both of the parallel blades l8 may havetherein an opening such as shown at 20. The bottom edge of the sides l8and the front l9 are sharpened to provide a cutting edge capable ofcutting through a pack of paper sheets to result in the form of slotsubstantially shown at 2| in Fig. 5.

As briefly explained hereinbefore, a camming edge is provided betweenthe sides of the slotting knife and in this particular instance Iprovide an insert 22, preferably formed of metal, which has a relativethickness capable of being beveled at its lower edge as at 23 downwardlyand toward the front of the knife. It will be evident, then, that as theknife is lowered through the pack and the paper chips are cut therefrom,as they are so cut they will engage the beveled or camming edge 23 andwill be urged away from the adjacent edge of the pack. As the chips moverearwardly and upwardly the side pressure thereon is relieved by theiredges expanding into the slots 20, and they will lie loose and fiat. Thesuction created in the tube 8 will then act completely to force thepaper chips away from the knife and remove them so completely from thearea of the table that a succeeding slotting operation will not beinterfered with. As stated heretofore, the suction method of removingthe chips has been attempted without the aid of either the openings inthe sides of the knife or the camming means therein. The efficiency ofthe vacuum in the tube 8 is increased tremendously by the aid of theopenings in the sides of the knife. These could be used alone withoutany camming means and satisfactory results would be acquired, but toinsure the greatest efiiciency I prefer also to include the cammingmeans just described.

With reference to Figs. 6 and 7 I have here disclosed a different formof slotting knife, but the invention itself remains the same. In thiscase I also provide a carriage ill to which the knife may be rigidlysecured by means of the screws Hi. In this case, however, theconfiguration of the knife is such as to provide the two parallelcutting blades 24 which are connected at their forward ends by astraight blade 25. This particular form of knife will cut a slot whichis known to the trade as the Kalamazoo slot. Here again each of the sideblades 24 is provided with openings 28a and against the inner side ofthe front blade 25 may be positioned one or more blocks or indentations26 having their lower edges beveled as at 21 to provide a camming edgeto urge the paper chips outwardly as they are being cut. The operationof this form of the invention is identical with that previouslyexplained but provides a different shaped slot.

In Figs. 8 to 12 are shown slotting knives which are intended to be usedin conjunction with a hollow drill. In these cases the drill and theslotting knife may be operated either separately or together. The resultbeing a substantially circular hole near the edge of the sheet of paperbut having a slot extending between the edge of the paper and thecircular hole. The operation of this form of machine is also fullydescribed in the co-pending application above referred to and it is onlynecessary here to describe in detail the slotting knife itself, inasmuchas that is where the invention resides. With particular respect to Figs.8 to 11, the tubular drill is shown at 28 adjacent which isthe slottingknife which has two divergingblades 29, which diverge rearwardly' fromadjacent-the lower end'of the tubular drill 28. These sideblades'2 9extend rearwardly for a considerable distance and are mounted in thevertically reciprocating carriage 30 by means of the screws 3!.

In this particular form of the invention the bottom of the knife isseparated into the two diverging blade portions 29 as clearly shown inFig. 11. These blades then extend upwardly for a short distance as at 32and are then joined by the connecting piece 33.which is curvedrearwardly and upwardly as at 34. Above this point the two divergingblade portions are integral and the curved portion 34 acts as a cammingedge which is integral with the knife and acts similarly to thosepreviously described to force the paper chips away from the blade andthe pack of paper sheets after they have been severed therefrom. Hereagain in the sides of the knife I provide openings 35 for the purpose ofacting in conjunction with the vacuumcreated in the tube 8 to completelyremove the chips from the knife for a succeeding operation.

In Fig. 12 is shown a further modification of the slotting knife whereinthe two diverging blades 29a are integral from the bottom edge all theway to the top and are secured to the carriage 36 by means similar tothat described heretofore. In this case an additional insert 31 isutilized at the front of the knife between the two diverging bladeswhich has a camming edge at the bottom thereof to urge the chipsrearwardly. The two blades of Fig. 12 also are provided with openingstherein for the same purpose described above.

It should also be noted'here that, while it is not considered necessary,it may be advisable to form the carriage H) as a solid portion 38 at therear side thereof which has an upwardly extending bottom edge as shownat 39. This has been found to increase the efliciency of the suction inthe tube 8 when the knife and carriage are at their lowest position bycutting off the air which may be drawn into the tube from places otherthan that immediatelyadjacent the slotting knife.

Other modes of applying the principle of my invention may be usedinstead of the one here described, change being made as regards thestructure herein disclosed provided, however, that the means stated byany of the following claims or the equivalent of such stated means beemployed.

I, therefore, particularly point out and distinctly claim, as myinvention:

1. In a paper slotting machine having a table to support a pack of papersheets to be slotted, and a vertically reciprocating carriage over saidtable. a slotting knife on said carriage movable therewith to andthrough said pack having blades thereon between which the paper chipsresulting by movement to and through said pack, said knife having sideblades thereon between which the resulting paper chips are received, anopening in each of said side blades, and suction means cooperating withsaid openings to forcibly remove the chips from between saidblades afterthe completion of each slotting operation.

3. The combination with apaper slotting machine having a table tosupport a pack of paper sheets, of a slotting knife movable to andthrough said pack to slot the sheets therein, said knife having cuttingblades thereon between which the resulting paper chips are received,openings in said blades, and suction means cooperating with saidopenings to thereby remove said chips from the knife.

4. The combination with a paper slotting machine having a table thereonto support a pack of paper sheets, of a slotting knife movable to andthrough said pack to cut slots in the sheets of paper therein, saidknife having opposed spaced apart cutting blades between which theresulting paper chips are received, openings in said blades, and suctionmeans adjacent said knife cooperating with said openings to therebyremove the chips from said knife.

5. The combination with a paper slotting machine having a table tosupport a pack of paper sheets, of a slotting knife adapted to slot theedges of said sheets by movement to and through said pack, an opening ina side of said knife,

and suction means cooperating with said opening to remove from saidknife the paper chips which result from the slotting operation.

6. The combination of elements defined in claim 5, combined with cammingmeans on said knife to move the paper chips away from the adjacent edgeof said pack as they are cut.

7. The combination with a paper slotting machine having a table tosupport a pack of paper sheets, of a slotting knife movable to andthrough said pack to slot the paper therein, said knife includingintegral diverging blades at the upper portion thereof, the connectingportion of said blades curving downwardly and outwardly at the bottomthereof and terminating in two separate blades, said downwardly andoutwardly curved portion acting as a cam to move away from said pack theresulting paper chips.

8. The combination of elements defined in claim 7, wherein each of saidblades has an opening therein, and suction means cooperating with saidopenings to thereby remove the paper chips completely from said knife.

9. The combination with a paper boring and slotting machine having apaper drill and a table to support a pack of paper sheets, of a slottingknife having a cutting edge located closely adjacent the cutting edge ofsaid drill and movable with said drill to and through said pack of papersheets, said knife having cutting blades between which the resultingpaper chips are received and camming means between said blades to movethe chips in a direction away from said drill and out from between saidblades.

10. The combination with a paper slotting machine having a table tosupport a pack of paper sheets, of a slotting knife movable to andthrough said pack to cut slots in the paper sheets therein, said knifehaving cutting blades between which the resulting paper chips arereceived and at least one of said blades having an exposed openingtherein, camming means between said blades to aid in forcing the chipsaway from the adjacent edge of the pack of paper sheets and suctionmeans cooperating with said opening in the blade to completely removethe chips from the knife.

11. In a paper slotting machine having a table to support a pack ofpaper sheets to be slotted, a slotting knife mounted for reciprocatingmovement relative to said table to and through said pack and havingblades between which the paper chips resulting from the operation arereceived and at least one of said blades having an exposed openingwhereby the pressure exerted by the blades upon the chips is relieved.

12. The elements in combination defined in claim 11 combined withcamming means between said blades to aid in releasing the chips frombetween the blades.

FREEMAN BARNEY.

